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<html lang="en">

<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
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  <title>7、访问 object 中的属性，将所有属性为 number 的全部相乘并输出。
  </title>
</head>

<body>
  <script>
    let arr = {
      num1: 12,
      num2: 2,
      num3: '12'
    }
    let sum = 1
    for (let i in arr) {
      if (typeof (arr[i]) === 'number') {
        sum *= arr[i]
      }
    }
    console.log(sum)
  </script>
</body>

</html>